Scientists have observed an increase in the presence of tropical fish in Nova Scotia, raising concerns about the potential impact on local species in the future. During a recent research expedition near Taylor Head Provincial Park on Nova Scotia’s Eastern Shore, DFO scientists encountered a cornetfish, typically found in the warmer Caribbean waters. Other tropical fish, such as the spotfin butterflyfish, were also discovered during these expeditions.
According to DFO scientist Ryan Stanley, while these species are not entirely new to the region, their frequency of appearance seems to be on the rise. Marine biology professor Boris Worm from Dalhousie University explained that warm-water currents and storms may be bringing these tropical fish northward, with some species actively seeking food sources and following the warm currents.
Worm highlighted that the influx of tropical and subtropical species into Atlantic waters could potentially provide a new food source for local marine life, benefiting larger predators like whales, seabirds, and seals. Although the cornetfish has not yet established itself as an invasive species in Nova Scotia, Worm noted its resemblance to the bluespotted cornetfish, an invasive species from the Indo-Pacific known for its impact on seagrass meadows and small fish populations.
The potential introduction of parasites by tropical fish species and other associated ecological changes underscore the importance of closely monitoring these developments in the ocean. Stanley emphasized the significance of tracking these warm-water species’ movements over time to understand and potentially mitigate their effects.
Utilizing environmental DNA testing, scientists can detect genetic material shed by passing fish, providing insights into the presence of species like the spotfin butterflyfish and triggerfish, even if they are not directly observed. This monitoring approach aids in understanding the evolving marine ecosystem dynamics in Nova Scotia.
Overall, the increasing presence of tropical fish in Nova Scotian waters highlights the need for ongoing research and vigilance to assess the ecological implications and potential long-term effects on local marine biodiversity.